Support is requested for a Keystone Symposia meeting entitled The Golden Anniversary of B Cell Discovery, organized by Patrick C. Wilson, Michael P. Cancro and Anne Durandy. The meeting will be held in Banff, Alberta, Canada from March 22-27, 2015. The general topic of this meeting is relevant to the NIAID mission with respect to the broad area of immune system research. The Keystone Symposia B Cells meeting is the premiere venue for B cell biologists and people interested in learning more about B cells. The 2015 meeting is unusually noteworthy, because it marks the golden anniversary of the discovery of B cells by Max Cooper and Robert Good in their classic Nature paper. Accordingly, we will honor the past 50 years of B cell study while focusing on the most up-to-date advances in B cell biology and antibody-meditated immunity. Each topical session will begin with a commentary on the history of the area, followed by presentations of the most current advances. Particular emphasis will be placed on B cell immunopoiesis in germinal centers, on the interaction of B cells with follicular-helper T cells, on antibody-mediated immunity to HIV and influenza, and on plasma and memory B cell biology. With this in mind, the presentation of unpublished data will be strongly encouraged. The goal will be to showcase the latest breakthroughs in B cell biology, antibody technologies, and the potential for B cell/antibody mediated vaccine development. Opportunities for interdisciplinary interactions will be significantly enhanced by the concurrent meeting on HIV Vaccines, which will share a keynote address and three plenary sessions with this meeting.